Create a rule titled “Investigating” with this text:

A living villager (the investigator) may secretly inform the mayor that they are investigating another living villager (the watched) once during each day.

A villager is “Out at Night” if it is night and one of the following is true of them:
1. They are the Night Watchman
2. They are a werewolf who has targeted another villager at some point during that night
3. They are “on the streets” per the Night Watchman rule
4. They are an Investigator (per this rule)

During each day, the Mayor shall privately inform each Investigator if their Watched was “Out at Night” on the previous night. In addition, if the Watched was a werewolf that targeted another villager during that night, their is a 50% chance that the Investigator witnessed this event, in which case the Mayor shall inform them that the Watched is a werewolf and inform them of one villager (selected randomly) whom the Watched targeted during that night.

Due to the concentration involved in investigating, and because investigators are often forced to sneak around in dark alleys to perform their work, investigators become easy targets for werewolves. An Investigator who would otherwise have immunity from being killed by werewolves loses that immunity. Otherwise an investigator that does not have immunity from being killed by werewolves may be killed by being targeted by a single werewolf (instead of the normal 2 required).

Investigators who are not careful can be seen by their Watched. When an Investigator selects their Watched, there is a 25% chance the watched will notice the Investigator following them home. The Mayor shall inform the Watched privately of the identity of the Investigator following them.

This rule provides a way to possibly gain valuable knowledge. However, by doing so you open yourself up to great risk. This also provides a means to bypass immunity to being killed (doctors, religious occupations, etc.)